We investigate the spin or charge transport in a one-dimensional strongly correlated system by using the adaptive time-dependent density-matrix renormalization-group method. The model we consider is a non-half-filled Hubbard chain with a bond of controllable spin-dependent electron hoppings, which is found to cause a blockade of spin current with little influence on charge current. We have considered (1) the spread of a wave packet of both spin and charge and (2) the spin and charge currents induced by a spin-dependent voltage bias. It is found that the spin-charge separation plays a crucial role in the spin-current blockade, which may be utilized to observe the spin-charge separation directly.We investigate the spin or charge transport in a one-dimensional strongly correlated system by using the adaptive time-dependent density-matrix renormalization-group method. The model we consider is a non-half-filled Hubbard chain with a bond of controllable spin-dependent electron hoppings, which is found to cause a blockade of spin current with little influence on charge current. We have considered (1) the spread of a wave packet of both spin and charge and (2) the spin and charge currents induced by a spin-dependent voltage bias. It is found that the spin-charge separation plays a crucial role in the spin-current blockade, which may be utilized to observe the spin-charge separation directly.

arXiv:0806.4494Physical Review BNov 26, 20083 citations

Impurities in spin chains

Stefan Rommer, Sebastian Eggert

Springer eBooksApr 6, 20080 citations

Closing of the spin gap and ferromagnetism induced by magnetic impurities

P. Schlottmann

The Hubbard chain with attractive $U$ and a finite concentration of magnetic impurities of spin $S$ is studied using the Bethe Ansatz technique. The impurities weaken the singlet bound states of the Hubbard model reducing the spin gap. The spin gap is closed at a critical concentration which depends on the spin and the coupling strength. A ferromagnetic phase is induced for concentrations of impurities larger than the critical one, where a fraction of singlet pairs is broken up giving rise to a Fermi sea of spin-polarized itinerant electrons.The Hubbard chain with attractive $U$ and a finite concentration of magnetic impurities of spin $S$ is studied using the Bethe Ansatz technique. The impurities weaken the singlet bound states of the Hubbard model reducing the spin gap. The spin gap is closed at a critical concentration which depends on the spin and the coupling strength. A ferromagnetic phase is induced for concentrations of impurities larger than the critical one, where a fraction of singlet pairs is broken up giving rise to a Fermi sea of spin-polarized itinerant electrons.

Physical review. B, Condensed matterMay 1, 19984 citations

Charge and spin dynamics of the Hubbard chains

Youngho Park, Shoudan Liang

arXiv:cond-mat/9907420Physica C SuperconductivityDec 1, 19990 citations

The spin-current blockade in Luttinger liquid

Yao Yao, Chang-Qin Wu

We investigate the spin-charge separation in the Luttinger liquid with a defective bond of controllable spin-dependent hopping by using the adaptive time-dependent density-matrix renormalization group method. The model is the non-half-filled Hubbard chain with this special bond, which is found to block the relevant spin current with little influence on charge current. We have considered the pure spin and charge currents induced by the voltage biases that are applied to the ideal leads attached at the ends of this Hubbard chain. The phenomenon is so robust that one may utilize it to observe the spin-charge separation directly.We investigate the spin-charge separation in the Luttinger liquid with a defective bond of controllable spin-dependent hopping by using the adaptive time-dependent density-matrix renormalization group method. The model is the non-half-filled Hubbard chain with this special bond, which is found to block the relevant spin current with little influence on charge current. We have considered the pure spin and charge currents induced by the voltage biases that are applied to the ideal leads attached at the ends of this Hubbard chain. The phenomenon is so robust that one may utilize it to observe the spin-charge separation directly.

Journal of Physics Conference SeriesFeb 1, 20090 citations

The Hubbard chain with attractive

U

and a finite concentration of magnetic impurities of spin

S

is studied using the Bethe Ansatz technique. The impurities weaken the singlet bound states of the Hubbard model reducing the spin gap. The spin gap is closed at a critical concentration which depends on the spin and the coupling strength. A ferromagnetic phase is induced for concentrations of impurities larger than the critical one, where a fraction of singlet pairs is broken up giving rise to a Fermi sea of spin-polarized itinerant electrons.